1. Technical Field
The present invention relates to a liquid coating method and a method for manufacturing an organic EL device.
2. Related Art
A liquid coating methods is described in a method for manufacturing a display device in which at least one of a plurality of function layers disposed between electrodes is formed by ejecting a liquid as droplets through a plurality of nozzles of a liquid ejecting head and the liquid ejecting head is scanned so that different nozzles eject droplets onto each region corresponding to the electrodes (Japanese Unexamined Patent Application Publication No. 2003-249355).
Since the liquid is ejected through different nozzles in this method, the variations in ejection amount among nozzles can be canceled. Consequently, the variation in amount of composition disposed between the electrodes is reduced.
Another liquid coating method is described in a method for controlling an ejection apparatus (Japanese Unexamined Patent Application Publication No. 2005-193104). The control method includes the first step of ejecting a viscous liquid from a head including a plurality of nozzles through which the viscous liquid is ejected and a plurality of pressure generating elements provided for the respective nozzles. A reference driving pulse is applied to each pressure generating element, thereby ejecting the viscous liquid through the nozzles. In a second step, the plurality of nozzles are divided into a plurality of groups according to the results of measurement for the weight of viscous liquid ejected through the nozzle, and a driving pulse having a waveform according to the group is applied to pressure generating elements corresponding to the nozzles in the group, thus ejecting the viscous liquid.
In the display device manufacturing method, the number of sequences of liquid ejecting head scanning is increased for aligning the positions of the different nozzles with each of the regions, in comparison with the case in which a single nozzle ejects liquid. This method is thus disadvantageous in increasing the productivity of liquid coating.
In the ejection apparatus controlling method, the number of driving pulses according to the weight of liquid ejected through the nozzle is increased as the number of nozzles is increased. Consequently, the driving circuit that generates the drive pulses to apply the pressure generating elements is undesirably complicated.